Effects of prenatal betamethasone exposure on regulation of stress physiology in healthy premature infants

Association of different doses of antenatal corticosteroids exposure with early major outcomes and early weight loss percentage in extremely preterm infants or extremely low birthweight infants: a multicentre cohort study

OBJECTIVES

To determine the dose-dependent associations between antenatal corticosteroids (ANS) exposure and the rates of major morbidities, and the early weight loss percentage (EWLP) in hospital among extremely preterm infants (EPI) or extremely low birthweight infants (ELBWI).

METHODS

A multicentre, retrospective cohort study of EPI or ELBWI born between 2017 and 2018 was conducted. Infants were classified into no ANS, partial ANS and complete ANS exposure group; three subgroups were generated by gestational age and birth weight. Multiple logistic regression and multiple linear regression were performed.

RESULTS

There were 725 infants included from 32 centres. Among no ANS, partial ANS and complete ANS exposure, there were significant differences in the proportions of bronchopulmonary dysplasia (BPD) (24.5%, 25.4% and 16.1%), necrotising enterocolitis (NEC) (6.7%, 2.0% and 2.0%) and death (29.6%, 18.5% and 13.5%), and insignificant differences in the proportions of intraventricular haemorrhage (IVH) (12.5%, 13.2% and 12.2%), and extrauterine growth restriction (EUGR) (50.0%, 56.6% and 59.5%). In the logistic regression, compared with no ANS exposure, complete ANS reduced the risk of BPD (OR 0.58, 95% CI 0.37 to 0.91), NEC (OR 0.21, 95% CI 0.08 to 0.57) and death (OR 0.36, 95% CI 0.23 to 0.56), and partial ANS reduced the risk of NEC (OR 0.23, 95% CI 0.07 to 0.72) and death (OR 0.54, 95% CI 0.34 to 0.87). Compared with partial ANS exposure, complete ANS decreased the risk of BPD (OR 0.58, 95% CI 0.37 to 0.91). There were insignificant associations between ANS exposure and IVH, EUGR. In the multiple linear regression, partial and complete ANS exposure increased EWLP only in the ≥28 weeks (w) and <1000 g subgroup (p<0.05).

CONCLUSIONS

Different doses of ANS (dexamethasone) exposure were protectively associated with BPD, NEC, death in hospital, but not EUGR at discharge among EPI or ELBWI. Beneficial dose-dependent associations between ANS (dexamethasone) exposure and BPD existed. ANS exposure increased EWLP only in the ≥28 w and<1000 g subgroup. ANS administration, especially complete ANS, is encouraged before preterm birth.

TRIAL REGISTRATION NUMBER

NCT06082414.

The high-expression programming of SR-B1 mediates adrenal dysfunction in female offspring induced by prenatal caffeine exposure and its cholesterol accumulation mechanism

The cholesterol metabolism and homeostasis of adrenal are important for steroidogenesis. Our previous studies found that prenatal caffeine exposure (PCE) can inhibit adrenal steroidogenesis in offspring, but whether the mechanism is related to local imbalance of cholesterol metabolism remains unknown. Here, we found that PCE inhibited adrenal steroidogenesis and increased the expression of cell pyroptosis and inflammatory-related indicators (NLRP3, caspase-1 and IL-1β) in female adult offspring rats, and at the same time, the cholesterol levels in serum and adrenal gland also significantly increased. In vitro, the high level of cholesterol could inhibit adrenal corticosteroid synthesis through pyroptosis and an inflammatory response. It suggested that the low adrenal steroidogenesis in PCE female adult offspring is related to local cholesterol accumulation-mediated pyroptosis and inflammation. Furthermore, dating back to the intrauterine period, PCE increased the serum CORT level in female fetal rats, and increased the expression of the adrenal cholesterol intake gene SR-B1, which persisted after birth and even into adulthood. At the cellular level, silencing SR-B1 could reverse the increase of intracellular cholesterol content caused by high levels of cortisol in NCI-H295R cells. Finally, we confirmed that high concentrations of glucocorticoids increased the expression and H3K14ac level of the promoter region in SR-B1 by upregulating the GR/SREBP1/p300 pathway in vivo and in vitro. In conclusion, we clarified that the high-expression programming of SR-B1 mediates adrenal dysfunction in PCE female offspring and its cholesterol accumulation mechanism, which provided a favorable basis for finding novel targets to prevent and treat fetal-originated diseases.

Increases in maternal depressive symptoms during pregnancy and infant cortisol reactivity: Mediation by placental corticotropin-releasing hormone

BACKGROUND

Maternal depressive symptoms in pregnancy may affect offspring health through prenatal programming of the hypothalamic-pituitary-adrenal (HPA) axis. The biological mechanisms that explain the associations between maternal prenatal depressive symptoms and offspring HPA axis regulation are not yet clear. This pre-registered investigation examines whether patterns of maternal depressive symptoms in pregnancy are associated with infant cortisol reactivity and whether this association is mediated by changes in placental corticotropin-releasing hormone (pCRH).

METHOD

A sample of 174 pregnant women completed assessments in early, mid, and late pregnancy that included standardized measures of depressive symptoms and blood samples for pCRH. Infant cortisol reactivity was assessed at 1 and 6 months of age.

RESULTS

Greater increases in maternal depressive symptoms in pregnancy were associated with higher cortisol infant cortisol reactivity at 1 and 6 months. Greater increases in maternal depressive symptoms in pregnancy were associated with greater increases in pCRH from early to late pregnancy which in turn were associated with higher infant cortisol reactivity.

CONCLUSIONS

Increases in maternal depressive symptoms and pCRH over pregnancy may contribute to higher infant cortisol reactivity. These findings help to elucidate the prenatal biopsychosocial processes contributing to offspring HPA axis regulation early in development.

Exposure to antenatal corticosteroids and infant cortisol regulation

Administration of antenatal corticosteroids (AC) is the standard of care during pregnancy for women who are at risk of early delivery. Evidence indicates that AC improve survival and reduce morbidity for preterm infants. However, research suggests that infants whose mothers receive AC have an altered hypothalamic-pituitary-axis (HPA) response to stressors in early life. Results are mixed regarding the nature of these effects, with studies showing both suppressed and augmented HPA activity. In addition, research is very limited beyond the 4th month of life. The purpose of this study was to determine if AC exposure was associated with infant cortisol levels in a resting state or in response to a stressor at 1, 6 and 12 months postnatal. We also evaluated the moderating role of preterm birth in this association. 181 women and their infants participated in the study. Women were recruited during the 3rd trimester of pregnancy; at this time, they completed the Perceived Stress Scale and provided 8 salivary samples over a 2-day period for cortisol assay. They provided these data again at 6 and 12 months postnatal. At 1, 6, and 12 months postnatal, salivary samples were collected from infants to examine their cortisol levels before and after participation in a 'stressor protocol'. Data were extracted from the medical record on AC exposure, gestational age, maternal obstetric risk, and neonatal morbidity. Mixed effects multilevel regression modeling was used to examine the aims. Infants whose mothers received AC had significantly lower resting state (B = -2.47, CI: -3.691, -0.0484) and post-stressor (B = -2.51, CI: -4.283, -0.4276) cortisol levels across the first year of life than infants whose mothers did not receive AC. There was no moderating effect of preterm birth on the relationship between AC exposure and cortisol. Results indicate a state of dampened HPA activation and cortisol hypo-arousal that persists across the first year of life among infants who were exposed to corticosteroids in utero. Further research is needed to examine mechanisms responsible for any alterations that occur during development of the fetal HPA axis, including epigenetic and biochemical factors that control hormonal secretion, negative feedback, and glucocorticoid receptor function throughout the HPA axis. Findings warrant careful consideration by obstetric clinicians of the benefits and risks of prescribing AC.

What Did the Neonatal Integrative Developmental Care Model and Routine Developmental Care Affect on Stress of Premature Babies?

BACKGROUND: Neonatal integrative developmental care model (NIDCM) is a holistic model of premature baby care referring to seven basic neuroprotective developmental cares (DCs) by involving the family. AIM: This study aimed to assess the effect of the application of NIDCM on the stress response of premature babies. METHODS: The research design used was quasi-experimental with a non-equivalent control group pre- and post-test. The study was conducted in the neonatal care room of Dr. Wahidin Sudirohusodo Makassar Hospital from January 2020 to April 2021. The sample was 76 subjects consisting of 38 premature babies (19 controls and 19 interventions) and 38 mothers (19 controls and 19 interventions). The collected samples were taken to the Medical Research Laboratory of Universitas Hasanuddin (HUMRC) for testing. Furthermore, baby stress was assessed from salivary cortisol levels by enzyme linked immunosorbent assay. In addition, the effect of initial cortisol, final cortisol, and birth weight on changes in salivary cortisol in premature babies was determined using the Chi-square test. RESULTS: Neither NIDCM intervention nor routine DC has been shown to descriptive statistically decrease the stress response of premature babies in the neonatal care room, some of which are even increased. However, specifically in premature babies with a birth weight of <1800 g, NIDCM showed a better effect in lowering cortisol after treatment than regular DC. CONCLUSIONS: The application of NIDCM intervention reduces the stressor felt by the babies in the neonatal care room, besides the condition of babies with a birth weight of fewer than 1800 g needs special attention with the NIDCM intervention.

Impact of antenatal corticosteroid exposure on thymus size in premature infants

BACKGROUND

This study examined the effect of corticosteroids on the thymic index (TI) and the thymus/weight index (TWI) in infants exposed to antenatal corticosteroids (ACS).

METHODS

This prospective study was conducted between August 2014 and October 2018. A thymus ultrasound was performed to assess thymus size on the second day of life. Thymus size was assessed as TI and TWI.

RESULTS

In total, 167 neonates (≤34 weeks gestation)  constituted the study population, including 94 ACS-exposed infants and 73 untreated infants. The treatment group exhibited significantly lower birth weight and significantly shorter birth length than the ACS (-) group. Therefore, TI was smaller in the treatment group than in the untreated group (6.96 ± 4.05 cm³ vs. 5.64 ± 3.39 cm³). The TWI was 3.69 ± 1.8 cm³/kg in the ACS (-) group versus 3.32 ± 1.56 cm³/kg in the ACS (+) group. The median anteroposterior diameter of the right lobe was 1.33 cm (range, 0.45-2.40) in the ACS (-) group compared to 1.15 cm (range, 0.47-2.40) in the ACS (+) group. The median anteroposterior diameter of the left lobe was 1.40 cm (range, 0.43-2.20) in the ACS (-) group and 1.19 cm (range, 0.32-2.36) in the ACS (+) group. The median largest sagittal area was 2.64 cm² (range, 0.5-5.46) in the ACS (-) group versus 2.20 cm² (range, 0.55-5.90) in the ACS (+) group.

CONCLUSION

We found that TWI was not significantly changed by ACS exposure in premature infants.

Major depression and generalised anxiety disorder: An analysis of the effects of remission status and comorbidity on mother-infant emotional availability in the perinatal period

BACKGROUND

The effects of maternal depression on mother-infant relationship quality likely vary according to depression heterogeneity. We investigated the effects of different presentations of major depression on mother-infant emotional availability (EA).

METHODS

Data were obtained from 115 mother-infant dyads from a longitudinal pregnancy cohort. Disorders, symptoms, and antidepressant use were assessed in pregnancy and postpartum, and EA was observed 6-month postpartum. Major Depressive Disorder (MDD) and Generalized Anxiety Disorder (GAD) were assessed using the Structured Clinical Interview for the DSM-5. A series of multivariate analyses of covariance analyses' examining the effects of disorder on EA were conducted.

RESULTS

After controlling for maternal age, antidepressant use, and postpartum depressive symptoms, MDD accounted for 20% of the variance in EA. In the MDD/GAD group, 93% of interactions were rated as emotionally unavailable, nearly threefold the comparison group rate.

CONCLUSIONS

Findings demonstrate that different presentations of major depression are associated with observed differences in mother-infant EA.

Cesarean delivery and infant cortisol regulation

BACKGROUND

Cesarean delivery reduces the risk of infant and maternal morbidity and mortality when medically indicated, however, the cesarean delivery rate is estimated to be two to three times higher than medically necessary. The World Health Organization and American College of Obstetricians and Gynecologists have expressed concern over the high rates of cesarean delivery, citing evidence that cesarean delivery has negative short- and long-term consequences for the health of the infant, mother, and for future pregnancies. Infants delivered by cesarean are at an increased risk of metabolic disease and immune dysfunction throughout the lifespan. Preliminary research suggests that the hypothalamic pituitary adrenal (HPA) axis is a plausible pathway linking cesarean delivery to poor health later in life. The present study examines the relation between mode of delivery and HPA axis function in six-month-old infants. We also examine whether the cesarean delivery was elective or indicated altered to the relation between mode of delivery and infant cortisol profiles.

METHODS

The sample included 136 mother/infant pairs. Thirty-nine women delivered by cesarean and 97 delivered vaginally. Maternal and infant medical records were reviewed for prenatal medical history and birth outcomes. Infant saliva was collected for cortisol analysis at a 6-month well-baby checkup. Samples were collected upon arrival to the appointment (baseline) and 20 min after exposure to a painful stressor, the inoculation procedure (response). A mixed model ANCOVA was conducted to determine whether salivary cortisol concentrations differed between the two delivery groups. To examine whether complications related to having an indicated cesarean delivery contributed to any association between mode of delivery and cortisol production, cortisol concentrations were compared between the subgroup of infants whose cesarean deliveries were elective (e.g. maternal request or previous cesarean delivery) to infants delivered vaginally.

RESULTS

Infants delivered by cesarean had lower cortisol concentrations at baseline and after the inoculation procedure compared to those delivered vaginally. Further, the relation between mode of delivery and cortisol levels persisted even when the analyses were restricted to compare only the elective cesarean deliveries (e.g. maternal request or previous cesarean delivery) to those delivered vaginally.

DISCUSSION

This study provides evidence for an association between cesarean delivery and infant HPA axis function in infancy. Findings are consistent with the hypothesis that the HPA axis is a plausible pathway that links cesarean delivery with long-term health outcomes.

Antenatal betamethasone and the risk of neonatal hypoglycemia: it's all about timing

INTRODUCTION

Our objective was to evaluate whether there is a relationship between the "time during the day" of maternal betamethasone administration between 24 and 34 weeks' gestation and the risk for neonatal hypoglycemia.

MATERIAL AND METHODS

A retrospective study included cases between 2008 and 2018. Eligible cases were pregnant women with singleton pregnancies who received a single course of betamethasone between 24 and 34 weeks' gestation. Each woman was allocated into one of four pre-defined groups based on the time when intramuscular betamethasone was administered. Group 1 (23:00-04:59) represents the lowest daily natural corticosteroids' activity, group 2 (05:00-10:59) represents the peak daily natural corticosteroids' activity, whereas group 3 (11:00-16:59) and group 4 (17:00-22:59) present an intermediate natural state of steady corticosteroids' secretion and activity. The primary outcome of the study was the incidence of neonatal hypoglycemia (glucose level of less than 40 mg/dL).

RESULTS

We have identified 868 women who received a single complete course of betamethasone, of which 353 women (40.7%) had a steroid treatment latency to delivery up to 14 days. The incidence of neonatal hypoglycemia was significantly higher in group 2 (39.5%, 30/76, p = 0.0063), compared to group 1, who had the lowest incidence of neonatal hypoglycemia (16.9%, 12/71), and to group 3 and group 4.

CONCLUSIONS

The "time during the day" when betamethasone administered is important when considering the risk for neonatal hypoglycemia. The risk was significantly higher when betamethasone was administered during the peak time and significantly lower when administered at the nadir time of maternal endogenous corticosteroid activity.

Basal serum cortisol concentration in very low birth weight infants

BACKGROUND

The aim of our study was to measure the basal serum cortisol concentration immediately after birth and to determine its association with perinatal factors and clinical outcomes in very low birth weight (VLBW) infants.

METHODS

Basal serum cortisol level was obtained within one hour after birth in inborn VLBW infants. The association between the basal serum cortisol level and perinatal and clinical outcomes was analyzed by comparing the groups with high versus low cortisol levels.

RESULTS

In total, 80 infants were included. The median concentration of basal serum cortisol was 167 nmol/L with an interquartile range of 98-298 nmol/L. The basal serum cortisol concentration positively correlated with elapsed time from the last betamethasone dose. Low serum cortisol concentration was associated with antenatal corticosteroid therapy, low lactic acid level, and low leukocyte count at birth. Basal serum cortisol level was not associated with mortality and neonatal morbidities including hypotension and severe grade intraventricular hemorrhage.

CONCLUSION

Both maternal corticosteroid therapy and perinatal distress may affect the basal serum cortisol concentration in VLBW infants early after birth.

[Early Life Stress]

Early Life Stress Stress and daily hassles are a normal part of day-to day-life. The amount of control that is experienced strongly contributes to resilience and coping. Children very frequently do not experience control over the stressors within their lives. Starting from pregnancy, they are subjected - via the maternal endocrine system - to a variety of stressors ranging from normal stress regarding the transition to parenthood to maternal abuse or torture. This article collects research of the last two decades regarding the influence of stress on the developing brain. Both, animal and human studies will shed light on the effect of pre- and postnatal stress demonstrating an influence of early life stressors reaching far into adulthood. A direct influence of stress on multiple developmental characteristics has been postulated and shown. The results of this review will underline the necessity of early life programs focusing stress reduction and resilience in children and their parents. Also, a need for programs targeting stress reduction in pregnancy will be demonstrated and emphasized.

Prenatal glucocorticoids exposure and fetal adrenal developmental programming

Clinically, we apply synthetic glucocorticoids to treat fetal and maternal diseases, such as premature labor and autoimmune diseases. Although its clinical efficacy is positive, the fetus will be exposed to exogenous synthetic glucocorticoids. Prenatal adverse environments (such as xenobiotics exposure, malnutrition, infection, hypoxia and stress) can cause fetuses overexposure to excessive endogenous maternal glucocorticoids. The level of glucocorticoids is the key to fetal tissue maturation and postnatal fate. A large number of studies have found that prenatal glucocorticoids exposure can lead to fetal adrenal dysplasia and dysfunction, continuing after birth and even into adulthood. As the core organ of fetal-originated adult diseases, fetal adrenal dysplasia is closely related to the susceptibility and occurrence of multiple chronic diseases, and there are also obvious gender differences. However, its intrauterine programming mechanisms have not been fully elucidated. This review summarizes recent advances in prenatal glucocorticoids exposure and fetal adrenal developmental programming alterations, which is of great significance for explaining adrenal developmental toxicity and the intrauterine origin of fetal-originated adult diseases.

Developmental programming of shyness: A longitudinal, prospective study across four decades

Although shyness is a ubiquitous phenomenon with early developmental origins, little research has examined the influence of prenatal exposures on the developmental trajectory of shyness. Here, we examined trajectories of shyness from childhood to adulthood in three groups (N = 254), with varying degrees of prenatal adversity as indicated by the number of stressful exposures: extremely low birth weight (ELBW; <1000 g) survivors prenatally exposed to exogenous corticosteroids (ELBW+S, n = 56); ELBW survivors not prenatally exposed to exogenous corticosteroids (ELBW+NS, n = 56); and normal birth weight (NBW, n = 142) controls. Multilevel modeling revealed that the ELBW+S individuals exhibited the highest levels of childhood shyness, which remained stable into adulthood. The ELBW+NS and NBW controls had comparably low levels of childhood shyness; however, the ELBW+NS individuals experienced patterns of increasing shyness, while NBW controls displayed decreases in shyness into adulthood. We speculate that individuals exposed to multiple prenatal stressors (i.e., ELBW+S) may be developmentally programmed to be more sensitive to detecting social threat, with one manifestation being early developing, stable shyness, while increasing shyness among ELBW+NS individuals may reflect a later developing shyness influenced by postnatal context. We discuss the implications of these findings for understanding the developmental origins and developmental course of human shyness from childhood through adulthood.

Can Placental Corticotropin-Releasing Hormone Inform Timing of Antenatal Corticosteroid Administration?

CONTEXT

Antenatal corticosteroids are commonly administered to pregnant women at risk for delivering between 23 and 34 gestational weeks; they provide crucial benefits to fetal lung maturation and reduce risk for neonatal morbidity and mortality. Corticosteroids are maximally efficacious for lung maturation when administered within 2 to 7 days of delivery. Accurately identifying the timing of preterm delivery is thus critical to ensure that antenatal corticosteroids are administered within a week of delivery and to avoid unnecessary administration to women who will deliver at term. A plausible biomarker for predicting time of delivery is placental corticotropin-releasing hormone (pCRH).

OBJECTIVE

To assess whether pCRH concentrations predict time to delivery and specifically which women will deliver within a week of treatment.

DESIGN

pCRH concentrations were evaluated before administration of the corticosteroid betamethasone, and timing of delivery was recorded.

PARTICIPANTS

A total of 121 women with singleton pregnancies who were prescribed betamethasone.

RESULTS

Elevated pCRH concentrations were associated with a shorter time from treatment to delivery. Receiver-operating characteristic curves revealed that pCRH may improve the precision of predicting preterm delivery.

CONCLUSIONS

In the current sample, pCRH concentrations predicted the likelihood of delivering within 1 week of corticosteroid treatment. Current findings suggest that pCRH may be a diagnostic indicator of impending preterm delivery. Increasing the precision in predicting time to delivery could inform when to administer antenatal corticosteroids, thus maximizing benefits and reducing the likelihood of exposing fetuses who will be delivered at term.

Effect of betamethasone, indomethacin and fenoterol on neonatal and maternal mononuclear cells stimulated with Escherichia coli

Despite considerable progress in the field of perinatal care, infectious diseases, especially when caused by gram negative bacteria, remain a major reason for neonatal morbidity and mortality. Notably infants born prematurely and those with very low birth weight are at risk due to their immature and deficient immune system and their prolonged hospitalization which promotes nosocomial infections. In case of impending preterm birth, betamethasone is given to induce lung maturation and tocolytic agents like indomethacin or fenoterol are administered to suppress premature labor. The aim of this study was to analyze the effects of these drugs on the immune system of mothers and neonates. Therefore, mononuclear cells from cord blood and peripheral maternal blood were stimulated with Escherichia coli and incubated with betamethasone, indomethacin and fenoterol. Subsequently the effect of the treatment on cytokine production was determined. Betamethasone alone and in combination with tocolytic agents inhibited the production of pro- and anti-inflammatory cytokines. Not only does betamethasone dampen the immune response by reducing the production of cytokines, it also has a variety of other detrimental short- and long-term effects on the neonate. In conclusion we would recommend using biological markers to determine if premature labor actually leads to preterm birth and subsequently administer betamethasone only to mothers giving birth prematurely.

Long-term impacts of prenatal synthetic glucocorticoids exposure on functional brain correlates of cognitive monitoring in adolescence

The fetus is highly responsive to the level of glucocorticoids in the gestational environment. Perturbing glucocorticoids during fetal development could yield long-term consequences. Extending prior research about effects of prenatally exposed synthetic glucocorticoids (sGC) on brain structural development during childhood, we investigated functional brain correlates of cognitive conflict monitoring in term-born adolescents, who were prenatally exposed to sGC. Relative to the comparison group, behavioral response consistency (indexed by lower reaction time variability) and a brain correlate of conflict monitoring (the N2 event-related potential) were reduced in the sGC exposed group. Relatedly, source localization analyses showed that activations in the fronto-parietal network, most notably in the cingulate cortex and precuneus, were also attenuated in these adolescents. These regions are known to subserve conflict detection and response inhibition as well as top-down regulation of stress responses. Moreover, source activation in the anterior cingulate cortex correlated negatively with reaction time variability, whereas activation in the precuneus correlated positively with salivary cortisol reactivity to social stress in the sGC exposed group. Taken together, findings of this study indicate that prenatal exposure to sGC yields lasting impacts on the development of fronto-parietal brain functions during adolescence, affecting multiple facets of adaptive cognitive and behavioral control.

Biobehavioral Responses of Preterm Infants to Conventional and Swaddled Tub Baths: A Randomized Crossover Trial

Bathing is a routine care procedure that exposes preterm infants to prolonged handling, which could cause stress and potentially disrupt infants' biobehavioral responses. The aim of this double-blind randomized crossover trial was to compare the preterm infant's body temperature, heart rate (HR), peripheral capillary oxygen saturation (SpO2), salivary cortisol levels, and sleep-wake states during and after swaddled and conventional tub baths. Forty-three infants born at 32 to 36 weeks postmenstrual age, weighing 2225 g or less, were enrolled in the study. Infants were videotaped before and after each type of baths. The time interval between baths ranged from 24 to 72 hours to allow a washout period. Physiological, hormonal, and behavioral responses were collected at baseline and during recovery from baths. No significant differences in the mean body temperature, HR, SpO2, salivary cortisol levels, and sleep-wake states between the bath types were observed in the baseline or recovery responses during the first 20 minutes after bath. Regardless of bath type, salivary cortisol levels showed a nonstatistical significant increase.

Developmental origins of the human hypothalamic-pituitary-adrenal axis

INTRODUCTION

The developmental origins of disease or fetal programming model predicts that intrauterine exposures have life long consequences for physical and psychological health. Prenatal programming of the fetal hypothalamic-pituitary-adrenal (HPA) axis is proposed as a primary mechanism by which early experiences are linked to later disease risk. Areas covered: This review describes the development of the fetal HPA axis, which is determined by an intricately timed cascade of endocrine events during gestation and is regulated by an integrated maternal-placental-fetal steroidogenic unit. Mechanisms by which stress-induced elevations in hormones of maternal, fetal, or placental origin influence the structure and function of the emerging fetal HPA axis are discussed. Recent prospective studies documenting persisting associations between prenatal stress exposures and altered postnatal HPA axis function are summarized, with effects observed beginning in infancy into adulthood. Expert commentary: The results of these studies are synthesized, and potential moderating factors are discussed. Promising areas of further research highlighted include epigenetic mechanisms and interactions between pre and postnatal influences.

Maternal sensitivity and adrenocortical functioning across infancy and toddlerhood: Physiological adaptation to context?

Theory suggests that early experiences may calibrate the "threshold activity" of the hypothalamus-pituitary-adrenal axis in childhood. Particularly challenging or particularly supportive environments are posited to manifest in heightened physiological sensitivity to context. Using longitudinal data from the Family Life Project (N = 1,292), we tested whether links between maternal sensitivity and hypothalamus-pituitary-adrenal axis activity aligned with these predictions. Specifically, we tested whether the magnitude of the within-person relation between maternal sensitivity and children's cortisol levels, a proxy for physiological sensitivity to context, was especially pronounced for children who typically experienced particularly low or high levels of maternal sensitivity over time. Our results were consistent with these hypotheses. Between children, lower levels of mean maternal sensitivity (7-24 months) were associated with higher mean cortisol levels across this period (measured as a basal sample collected at each visit). However, the magnitude and direction of the within-person relation was contingent on children's average levels of maternal sensitivity over time. Increases in maternal sensitivity were associated with contemporaneous cortisol decreases for children with typically low-sensitive mothers, whereas sensitivity increases were associated with cortisol increases for children with typically high-sensitive mothers. No within-child effects were evident at moderate levels of maternal sensitivity.

Failure of Saliva Sampling in the QF2011 Queensland Flood Study Examining the Effects of Prenatal Maternal Stress on Neonatal Stress Reactivity

The study was designed to investigate the impact of disaster-related prenatal maternal stress on neonates’ reactivity to the routinely administered, painful, newborn screen procedure (heelstick or heel prick). We hypothesized that pregnancy exposure to a flood stressor would affect fetal developmental pathways and subsequently neonatal responses to other stressful events, including the newborn screen. The pregnant women we recruited were affected by sudden onset floods in Queensland, Australia in 2011. Using methods similar to those described in the literature, we collected neonatal saliva immediately prior to the newborn screen and +20 and +40 min afterwards. Saliva sampling was halted after failed saliva collection attempts by trained research staff on 17 newborns. This article discusses reasons for our failure, including the influence of bioethical concerns and the requirement that research activities are compliant with hospital policies as well as the necessity of publishing studies that fail to replicate prior research.

Antenatal glucocorticoid treatment is associated with diurnal cortisol regulation in term-born children

Due to the rapid developmental changes that occur during the fetal period, prenatal influences can affect the developing central nervous system with lifelong consequences for physical and mental health. Glucocorticoids are one of the proposed mechanisms by which fetal programing occurs. Glucocorticoids pass through the blood-brain barrier and target receptors throughout the central nervous system. Unlike endogenous glucocorticoids, synthetic glucocorticoids readily pass through the placental barrier to reach the developing fetus. The synthetic glucocorticoid, betamethasone, is routinely given prenatally to mothers at risk for preterm delivery. Over 25% of the fetuses exposed to betamethasone will be born at term. Few studies have examined the lasting consequences of antenatal treatment of betamethasone on the regulation of the hypothalamic-pituitary-adrenal (HPA) axis. The purpose of this study is to examine whether antenatal exposure to betamethasone alters circadian cortisol regulation in children who were born full term. School-aged children prenatally treated with betamethasone and born at term (n=19, mean (SD)=8.1 (1.2) years old) were compared to children not treated with antenatal glucocorticoids (n=61, mean (SD)=8.2 (1.4) years old). To measure the circadian release of cortisol, saliva samples were collected at awakening; 30, 45, and 60min after awakening; and in the evening. Comparison children showed a typical diurnal cortisol pattern that peaked in the morning (the cortisol awakening response) and gradually decreased throughout the day. In contrast, children exposed to antenatal betamethasone lacked a cortisol awakening response and had a flatter diurnal slope (p's<0.01). These data suggest that antenatal glucocorticoid treatment may disrupt the circadian regulation of the HPA axis among children born at term. Because disrupted circadian regulation of cortisol has been linked to mental and somatic health problems, future research is needed to determine whether children exposed to antenatal synthetic glucocorticoids are at risk for poor mental and physical health.

Salivary Cortisol Reactivity in Preterm Infants in Neonatal Intensive Care: An Integrative Review

Recently, more and more researchers have been using salivary cortisol reactivity to evaluate stress in preterm infants in the neonatal intensive care unit (NICU). The aim of this integrative literature review was to summarize the evidence of interventions leading to a change in salivary cortisol from the baseline in preterm infants in the NICU. The electronic databases of PubMed, CINAHL, Web of Science, and Scopus were searched for relevant studies. The inclusion criteria were studies with preterm infants exposed to an intervention evaluated by salivary cortisol reactivity before discharge from the NICU, which were published in English. In total, 16 studies were included. Eye-screening examination and heel lance provoked an increase in the salivary cortisol level. Music, prone position, and co-bedding among twins decreased the salivary cortisol level. Several studies reported a low rate of successful saliva sampling or did not use control groups. Future studies need to focus on non-painful interventions in order to learn more about salivary cortisol regulation in preterm infants. Moreover, these studies should use study designs comprising homogenous gestational and postnatal age groups, control groups, and reliable analysis methods that are able to detect cortisol in small amounts of saliva.

Tailored Assays for Pharmacokinetic and Pharmacodynamic Investigations of Aliskiren and Enalapril in Children: An Application in Serum, Urine, and Saliva

OBJECTIVES

Drugs that are effectively used to treat hypertension in adults (e.g., enalapril) have not been sufficiently investigated in children. Studies required for pediatric approval require special consideration regarding ethics, study design, and conduct and are also associated with special demands for the bioanalytic method. Pediatric-appropriate assays can overcome these burdens and enable systematic investigations of pharmacokinetics and pharmacodynamic in all pediatric age groups.

METHODS

Tailored assays were developed for pharmacokinetic investigation of a drug in 100 μL of serum, saliva, and urine. All assays were applied in a proof-of-concept study to 22 healthy volunteers who had been given 300 mg aliskiren hemifumarate or 20 mg enalapril maleate and allowed for dense sampling. Changes in humoral parameters of the renin-angiotensin-aldosterone system were also evaluated with 6 parameters in 2.1 mL blood per time point.

RESULTS

The pharmacokinetic results of aliskiren and enalapril obtained by low-volume assays in serum and urine were comparable to that noted in the literature. The dense sampling enabled very detailed concentration-time profiles that showed high intersubject variability and biphasic absorption behavior of aliskiren. The replacement of invasive sampling by saliva collection appears inappropriate for both drugs because the correlations of drug concentrations in both fluids were low. A low-volume assay was also used to determine values for in the renin-angiotensin-aldosterone system and to compare those results with the published literature.

CONCLUSION

These results support both the use of low-volume assays in pediatric research and the systematic investigation of their use in neonates and infants. Use of this assay methodology will increase information about drug pharmacokinetics and pharmacodynamics in this vulnerable population and might contribute to safe and effective use of pharmacotherapy.

Activity of the hypothalamus-pituitary-interrenal axis (HPI axis) and immune response in carp lines with different susceptibility to disease

The stress response transmitted by the HPA axis is one of the best examples of neuroendocrine-immune interactions that are critical for survival. Analogous to the situation in mammals, the stress response in fish is characterized by the activation of the hypothalamo-pituitary-interrenal axis (HPI). Effects of cortisol on the fish immune system comply with findings in mammals and suggest that the differences in sensitivity to stress will influence the immune response and as a consequence of survival. Therefore, we studied the stress response and its immunity-related effects in four different carp lines (R3, R3xR8, K and R2) that display a differential pathogen susceptibility. Previous studies indicate that R3xR8 and R3 carp are susceptible to bacterial and parasite infection, while R2 and K are relatively resistant to infection. Interestingly, the most striking effect of stress on leukocyte composition and activity was observed in the pathogen-resistant K carp, even though no robust changes in gene expression of stress-involved factors were observed. In contrast, R3 carp showed no spectacular stress-induced changes in their immunological parameters with concurrent significant activation of the HPI axis. Upon stress, the R3 carp showed up-regulation of crf, pomc and gr2 gene expression in the hypothalamus. Furthermore in R3 carp, at all levels of the HPI axis, stress induced the highest up-regulation of il-1β gene expression. Although we are aware of the complexity of the interactions between stress and pathogen susceptibility and of the risk of interpretation based on correlations, it is noteworthy that the fish more susceptible to infection also exhibited the highest response to stress.

Increased maternal nighttime cortisol concentrations in late gestation alter glucose and insulin in the neonatal lamb

Previous studies in our laboratory have shown that a modest chronic increase in maternal cortisol concentrations impairs maternal glucose metabolism and increases the incidence of perinatal stillbirth. The dramatic outcomes prevented our ability to study the effects of maternal hypercortisolemia on neonatal growth, glucose metabolism, and hypothalamo–pituitary–adrenal axis response. Therefore, we developed a model in which pregnant ewes are infused for 12 h/day at 0.5 mg·kg^–1·day^–1 from day 115 of gestation until delivery (˜145), elevating nighttime plasma cortisol concentrations. This pattern of elevation of cortisol mimics that in patients with elevated evening cortisol concentrations, as in Cushing’s syndrome or chronic depression. Plasma cortisol, glucose, insulin, and electrolytes were measured during pregnancy and postpartum in control and cortisol-infused ewes and their postnatal lambs for the first 14 days after delivery. Neonatal growth and plasma ACTH, aldosterone, renin activity, and electrolytes, and organ weights at 14 days of age were also measured. Infusion of cortisol increased maternal plasma cortisol during pregnancy but not postpartum, and did not alter neonatal ACTH or cortisol. Although maternal glucose and insulin concentrations were not changed by the maternal infusion of cortisol, neonatal plasma glucose was increased and plasma insulin was decreased compared to those in the control group. Neonatal ponderal index and kidney weight were reduced, left ventricular wall thickness was increased, and plasma sodium and creatinine were increased after maternal cortisol infusion. These results suggest that excess maternal cortisol concentrations in late gestation alter growth, glucose and insulin regulation, and organ maturation in the neonate.

Effects of Antenatal Corticosteroids on Cortisol and Heart Rate Reactivity of Preterm Infants

Administration of glucocorticoids (GCs) during pregnancy is an established practice for reducing morbidity and mortality of fetuses at risk of preterm delivery. However, preliminary research indicates that exposure to exogenous GCs in utero may be associated with suppressed hypothalamic–pituitary–adrenal axis activity. The aim of this study was to determine whether preterm neonates who are exposed to antenatal corticosteroids show evidence of a suppressed stress-response system during their first few weeks of life, in contrast to infants who are not exposed. The sample (51% female) included 57 neonates, with 74% exposed to steroids. Mean gestational ages (GAs) were 32.6 weeks for exposed and 34.7 weeks for nonexposed infants. Although neonates in the two groups differed in gender, birth weight, and morbidity, these factors were controlled for in data analyses. Infants’ salivary cortisol and heart rate (HR) were measured before and after they received a standardized caregiving “stressor” while in the newborn intensive care unit. Infants exposed to GCs in utero had lower basal cortisol levels and higher HRs than their nonexposed peers. In contrast to infants who received no GCs, they also exhibited minimal HR or cortisol reactivity to the stressor. Findings suggest that preterm infants who were exposed to antenatal corticosteroids experience a suppressed response to stress. As preterm children develop, this dysregulation has numerous implications for later development of stress-related cardiovascular and mental health problems. Further research is needed to determine whether these postnatal effects of antenatal corticosteroids persist over time.

Peripartum depression and anxiety as an integrative cross domain target for psychiatric preventative measures

Exposure to high levels of early life stress has been identified as a potent risk factor for neurodevelopmental delays in infants, behavioral problems and autism in children, but also for several psychiatric illnesses in adulthood, such as depression, anxiety, autism, and posttraumatic stress disorder. Despite having robust adverse effects on both mother and infant, the pathophysiology of peripartum depression and anxiety are poorly understood. The objective of this review is to highlight the advantages of using an integrated approach addressing several behavioral domains in both animal and clinical studies of peripartum depression and anxiety. It is postulated that a greater focus on integrated cross domain studies will lead to advances in treatments and preventative measures for several disorders associated with peripartum depression and anxiety.

Glucocorticoids and fetal programming part 1: Outcomes

Fetal development is a critical period for shaping the lifelong health of an individual. However, the fetus is susceptible to internal and external stimuli that can lead to adverse long-term health consequences. Glucocorticoids are an important developmental switch, driving changes in gene regulation that are necessary for normal growth and maturation. The fetal hypothalamic-pituitary-adrenal (HPA) axis is particularly susceptible to long-term programming by glucocorticoids; these effects can persist throughout the life of an organism. Dysfunction of the HPA axis as a result of fetal programming has been associated with impaired brain growth, altered behaviour and increased susceptibility to chronic disease (such as metabolic and cardiovascular disease). Moreover, the effects of glucocorticoid-mediated programming are evident in subsequent generations, and transmission of these changes can occur through both maternal and paternal lineages.

Antenatal steroids: can we optimize the dose?

PURPOSE OF REVIEW

The beneficial effects of antenatal steroids in women at risk of preterm birth are evident. A dose of 24 mg appears sufficient, but there are insufficient data to recommend betamethasone or dexamethasone, a single steroid dose, the optimal interval between doses and repeated courses, the gestational age at which treatment is beneficial and the long-term effects of steroid treatment. This review addresses these aspects of antenatal steroid treatment.

RECENT FINDINGS

Although the 12-h and 24-h dosing intervals are equivalent with respect to prevention of respiratory distress syndrome, the former enables the completion of treatment in 50% more neonates delivered prematurely. Reducing the single steroid dose in patients at risk for premature birth reduces the associated maternal side effects. An inverse relationship has been demonstrated between the number of corticosteroid courses and foetal growth. The reduced size of exposed foetuses has been attributed to birth at earlier gestational ages and decreased foetal growth. Evidence suggests that antenatal exposure to synthetic glucocorticoids in term-born children has long-lasting effects, which may have important implications in the recommendation of steroids before elective caesarean at term.

SUMMARY

The short-term and long-term effects of the dosage regimen on the pregnant mother and foetus remain unclear.

Measurement of salivary cortisol as a marker of stress in newborns in a neonatal intensive care unit

AIMS

The study was designed to evaluate the newborn (NB) stress response during the inpatient time in the neonatal intensive care unit.

METHODS

A quantitative, prospective, observational study was conducted with two NB groups. The first group consisted of 12 NB patients in the neonatal intensive care unit as the experimental group (EG), and the second included 43 NBs who were sent to their own homes and were considered the control group (CG). The EG's salivary cortisol concentration was measured on the 2nd day (D2) and 9th day (D9) of life. The CG's salivary cortisol concentration was measured on the 14th day of life at the child's own home.

RESULTS

The salivary cortisol concentration levels for the EG on D2 and D9 and for the CG were 4.3151 ± 2.6492, 1.826 ± 1.2252, and 1.0166 ± 0.8300 ng/dl, respectively. These findings indicated the presence of an adrenal response to stress during the first inpatient days.

CONCLUSIONS

The salivary cortisol concentration is an accurate method to indicate neonatal stress. The glucocorticoids frequently used in the prenatal period suppress the adrenal glands and interfere with the stress response.

Prenatal corticosteroids modify glutamatergic and GABAergic synapse genomic fabric: insights from a novel animal model of infantile spasms

Prenatal exposure to corticosteroids has long-term postnatal somatic and neurodevelopmental consequences. Animal studies indicate that corticosteroid exposure-associated alterations in the nervous system include hypothalamic function. Infants with infantile spasms, a devastating epileptic syndrome of infancy with characteristic spastic seizures, chaotic irregular waves on interictal electroencephalogram (hypsarhythmia) and mental deterioration, have decreased concentrations of adrenocorticotrophic hormone (ACTH) and cortisol in cerebrospinal fluid, strongly suggesting hypothalamic dysfunction. We have exploited this feature to develop a model of human infantile spasms by using repeated prenatal exposure to betamethasone and a postnatal trigger of developmentally relevant spasms with NMDA. The spasms triggered in prenatally primed rats are more severe compared to prenatally saline-injected ones and respond to ACTH, a treatment of choice for infantile spasms in humans. Using autoradiography and immunohistochemistry, we have identified a link between the spasms in our model and the hypothalamus, especially the arcuate nucleus. Transcriptomic analysis of the arcuate nucleus after prenatal priming with betamethasone but before trigger of spasms indicates that prenatal betamethasone exposure down-regulates genes encoding several important proteins participating in glutamatergic and GABAergic transmission. Interestingly, there were significant sex-specific alterations after prenatal betamethasone in synapse-related gene expression but no such sex differences were found in prenatally saline-injected controls. A pairwise relevance analysis revealed that, although the synapse gene expression in controls was independent of sex, these genes form topologically distinct gene fabrics in males and females and these fabrics are altered by betamethasone in a sex-specific manner. These findings may explain the sex differences with respect to both normal behaviour and the occurrence and severity of infantile spasms. Changes in transcript expression and their coordination may contribute to a molecular substrate of permanent neurodevelopmental changes (including infantile spasms) found after prenatal exposure to corticosteroids.

Human milk cortisol is associated with infant temperament

The implications of the biologically active elements in milk for the mammalian infant are largely unknown. Animal models demonstrate that transmission of glucocorticoids through milk influences behavior and modifies brain development in offspring. The aim of this study was to determine the relation between human milk cortisol levels and temperament of the breastfed infant. Fifty-two mother and infant pairs participated when the infants were three-months old. Milk cortisol levels were assessed and each mother completed the Infant Behavior Questionnaire (IBQ), a widely used parent-report measure of infant temperament. Analyses revealed a positive association between milk cortisol and the negative affectivity dimension of the IBQ (partial r=.37, p<.01). No correlation was found between elevated cortisol levels and the surgency/extraversion or the orienting/regulation dimensions. Further, the positive association between increased maternal milk cortisol and negative affectivity was present among girls (β=.59, p<.01), but not among boys. (Although, the sex by milk cortisol interaction term was not statistically significant, suggesting that these results require replication.) Environmental factors such as maternal demographics and negative maternal affect (depression and perceived stress) at the time of assessment did not account for the positive association. The findings support the proposal that exposure to elevated levels of cortisol in human milk influences infant temperament. The findings further suggest that mothers have the ability to shape offspring phenotype through the transmission of biologically active components in milk.

A novel method of collection of saliva for estimation of steroid levels in extremely premature infants

AIM

The major advantage of salivary cortisol sampling is that it is considerably less invasive than taking a blood sample. However, previous methods of obtaining saliva in premature infants have been poorly tolerated and inaccurate. We describe a simple, non-distressing technique for obtaining saliva samples to assess extremely premature infants' salivary cortisol status.

METHODS

We prospectively obtained early morning saliva samples from extremely premature infants. Their gestational age ranged between 23 and 27 weeks. Saliva was obtained using four standard universal swabs by placing one swab at a time in the infant's mouth for 1-2 min. No salivary stimulants were used.

RESULTS

There were 65 infants (36 males). Mean gestation was 25.3 ± 1.3 weeks. This technique had a success rate of 85% in obtaining a mean of 150 μL of saliva (range 50-350 μL) by trained staff. No adverse events were recorded.

CONCLUSION

We describe a novel, safe, non-distressing and effective method of saliva collection for salivary cortisol measurement in extremely premature infants.

Effects of antenatal corticosteroids on the hypothalamic-pituitary-adrenocortical axis of the fetus and newborn: experimental findings and clinical considerations

The hypothalamic-pituitary-adrenocortical (HPA) axis is a major neuroendocrine pathway that modulates the stress response. The glucocorticoid, cortisol, is the principal end product of the HPA axis in humans and plays a fundamental role in maintaining homeostasis and in fetal maturation and development. Antenatal administration of synthetic glucocorticoids (GCs) accelerates fetal lung maturation and has significantly decreased neonatal mortality and morbidity in infants born before 34 weeks of gestation. Exposure to excess levels of endogenous GCs and exogenous GCs (betamethasone and dexamethasone) has been shown to alter the normal development trajectory. The development and regulation of the fetal HPA axis is discussed and the experimental animal evidence presented suggests long-term adverse consequences of altered HPA function. The clinical data in infants exposed to GCs also suggest altered HPA axis function over the short term. The longer-term consequences of antenatal GC exposure on HPA axis function and subtler neurodevelopmental outcomes including adaptation to stress, cognition, behavior, and the cardiovascular and immune responses are poorly understood. Emerging clinical strategies and interventions may help in the selection of mothers at risk for preterm delivery who would benefit from existing or future formulations of antenatal GCs with a reduction in the associated risk to the fetus and newborn. Detailed longitudinal long-term follow-up of those infants exposed to synthetic GCs are needed.

Nasopharyngeal suctioning does not produce a salivary cortisol reaction in preterm infants

AIM

To investigate whether nasopharyngeal suctioning produces a physiological and behavioural stress reaction in preterm infants and if a possible reaction can be dampened by sweet solution.

METHODS

Eleven preterm infants were randomly assigned to receive either 30% oral glucose or nothing prior to morning nasopharyngeal suctioning; the procedure was reversed in the afternoon. The study included a total of 44 samples from preterm infants evaluated with salivary cortisol, pain score (Visual Analogue Scale), heart rate, oxygen saturation and recovery time through the Newborn Individualized Developmental Care and Assessment Program. For reference, 44 samples from eleven full-term infants were evaluated for salivary cortisol.

RESULTS

Regardless of whether or not preterm infants received glucose before nasopharyngeal suctioning, no statistically significant difference was found in salivary cortisol reactivity, pain score, heart rate, oxygen saturation or recovery time. Nor were any statistically significant differences between salivary cortisol baseline and response values found in full-term infants after nasopharyngeal suctioning.

CONCLUSION

In the present setting, nasopharyngeal suctioning was not stressful enough to increase salivary cortisol or pain score. Oral glucose did not alter salivary cortisol levels.

Alterations in stress responses of the hypothalamic-pituitary-adrenal axis in small for gestational age infants

Mounting epidemiologic evidence and animal models suggest that stressful conditions during the intrauterine period may increase susceptibility to several adult conditions, including metabolic syndrome, cardiovascular disease, and psychiatric disorders. Increased cortisol levels due to alterations in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis are believed to be one mediating mechanism. Infants born after significant exposure to stressful conditions are often small for gestational age (SGA) based on standardized growth norms. Lifelong programming of the HPA axis has been proposed as a mechanism to explain the association between SGA infants and adult disease. However, few studies have measured HPA axis function proximal to birth as done in this study of SGA infants during the first week of life. Participants included 37 infants in two groups based on birth size (gestational age range: 34-41weeks). SGA infants were <10th percentile for age (n=21) and appropriate for gestational age (AGA) infants (n=16) were from 20 to 90th percentile for age. Cortisol response to a heel lance for blood collection was measured for all infants. Hierarchical Linear Modeling was used to test the effect of AGA/SGA group status on cortisol trajectories in response to the stressor. Group was a significant predictor of quadratic slopes (t=2.84, χ(2)=8.19, p=.004) after controlling for the effect of group on intercepts and linear slopes. Predicted growth curves for ln-cortisol were plotted for each group based on regression coefficients. The predicted curves capture the significant group difference in trajectories, as well as the blunted response for the SGA group and the robust peak in cortisol production in response to the stressor for the AGA group. This evidence suggests SGA neonates have blunted HPA axis responses to stressors in comparison to AGA infants. These findings are consistent with animal models showing that adverse intrauterine conditions can result in blunted cortisol responses to acute stressors and may provide a mechanism for adult susceptibility to disease for individuals that are SGA at birth.

Prenatal psychobiological predictors of anxiety risk in preadolescent children

Experimental animal models have demonstrated that one of the primary consequences of prenatal stress is increased fear and anxiety in the offspring. Few prospective human studies have evaluated the consequences of prenatal stress on anxiety during preadolescence. The purpose of this investigation is to determine the consequences of prenatal exposure to both maternal biological stress signals and psychological distress on anxiety in preadolescent children. Participants included 178 mother-child pairs. Maternal psychological distress (general anxiety, perceived stress, depression and pregnancy-specific anxiety) and biological stress signals were evaluated at 19, 25, and 31 gestational weeks. Anxiety was evaluated in the children at 6-9 years of age using the Child Behavior Checklist. Analyses revealed that prenatal exposure to elevated maternal cortisol, depression, perceived stress and pregnancy-specific anxiety was associated with increased anxiety in children. These associations remained after considering obstetric, sociodemographic and postnatal maternal psychological distress; factors that could influence child development. When all of the prenatal measures were considered together, cortisol and pregnancy-specific anxiety independently predicted child anxiety. Children exposed to elevated prenatal maternal cortisol and pregnancy-specific anxiety were at an increased risk for developing anxiety problems during the preadolescent period. This project identifies prenatal risk factors associated with lasting consequences for child mental health and raises the possibility that reducing maternal distress during the prenatal period will have long term benefits for child well-being.

The Stockholm Neonatal Family-Centered Care Study: effects on salivary cortisol in infants and their mothers

BACKGROUND

Parental involvement in the care of preterm infants in neonatal intensive care units (NICUs) is common, but little is known about the effect on stress responses in mothers and infants.

AIMS

The aim of this study is to evaluate the effect of family-centered care on salivary cortisol reactivity in mothers and preterm infants and the correlation between the mothers' and the preterm infants' salivary cortisol levels.

METHODS

This study is part of a randomized controlled trial conducted at two level-II NICUs, including Family Care (FC), where parents were able to stay 24h/day from admission to discharge, and Standard Care (SC). To investigate the cortisol response, saliva was collected from 289 preterm infants and their mothers before and after a diaper change at the time of discharge.

RESULTS

No significant differences were found between the two groups in salivary cortisol reactivity, either in mothers or in infants. The results revealed a correlation between preterm infants' and their mothers' baseline and response cortisol in the FC group: r=0.31 (p=0.001) and r=0.24 (p=0.01), respectively. Such correlation was not observed in the SC group: r=0.14 (p=0.14) and r=0.18 (p=0.07), respectively.

CONCLUSIONS

Family-centered care had no effect on salivary cortisol reactivity during diaper change. However, sharing the same environment may increase the concordance between preterm infants' and their mothers' salivary cortisol levels.

Neurobehavioral risk is associated with gestational exposure to stress hormones

The developmental origins of disease or fetal programming model predict that early exposures to threat or adverse conditions have lifelong consequences that result in harmful outcomes for health. The maternal endocrine 'fight or flight' system is a source of programming information for the human fetus to detect threats and adjust their developmental trajectory for survival. Fetal exposures to intrauterine conditions including elevated stress hormones increase the risk for a spectrum of health outcomes depending on the timing of exposure, the timetable of organogenesis and the developmental milestones assessed. Recent prospective studies, reviewed here, have documented the neurodevelopmental consequences of fetal exposures to the trajectory of stress hormones over the course of gestation. These studies have shown that fetal exposures to biological markers of adversity have significant and largely negative consequences for fetal, infant and child emotional and cognitive regulation and reduced volume in specific brain structures.

Single course of antenatal steroids did not alter cortisol in preterm infants up to 18 months

AIMS

To determine whether a single course of antenatal dexamethasone alters resting cortisol at 3, 8 and 18 months corrected age in preterm infants.

METHODS

Preterm infants born ≤32 weeks gestational age were recruited during 2001-2004 from a single neonatal intensive care unit. Resting salivary cortisol was collected at least once at 3, 8 and 18 months corrected age in a longitudinal cohort. A mixed-effects repeated measures analysis was used to accommodate cases with less than complete follow-up.

RESULTS

One hundred and thirty three infants were included in the present study, contributing 266 cortisol samples. Of these, 107 infants had been exposed to a single course of antenatal dexamethasone and 26 not exposed to antenatal steroids. There was no significant main effect of antenatal steroids on resting cortisol at any age. This result was not altered after adjusting for gestational age at birth, neonatal cumulative pain, morphine exposure, mechanical ventilation days and post-natal steroid exposure.

CONCLUSIONS

No effect of a single course of dexamethasone on resting salivary cortisol, an indicator of hypothalamic-pituitary-adrenal axis function, was found in infancy up to 18 months corrected age in infants born very preterm.

Glucocorticoid exposure of sheep at 0.7 to 0.75 gestation augments late-gestation fetal stress responses

OBJECTIVES

Exposure to glucocorticoid levels inappropriately high for current maturation alters fetal hypothalamo-pituitary-adrenal axis (HPAA) development. In an established fetal sheep model, we determined whether clinical betamethasone doses used to accelerate fetal lung maturation have persistent effects on fetal HPAA hypotensive-stress responses.

STUDY DESIGN

Pregnant ewes received saline (n = 6) or betamethasone (n = 6); 2 × 110 μg/kg body weight doses injected 24 hours apart (106/107 and 112/113 days' gestational age, term 150 days). Basal adrenocorticotropin (ACTH) and cortisol and responses to fetal hypotension were measured before and 5 days after the first course and 14 days after the second course.

RESULTS

Basal ACTH and cortisol were similar with treatment. HPAA responses to hypotension increased after the second but not first course and ACTH/cortisol ratio increased indicating central HPAA effects.

CONCLUSIONS

Results demonstrate latency in the emergence of fetal HPAA hyperresponsiveness following betamethasone exposure that may explain hyperresponsiveness in full-term but not preterm neonates.

Regulation of corticoid and serotonin receptor brain system following early life exposure of glucocorticoids: long term implications for the neurobiology of mood

Potent glucocorticoids (GC) administered early in life have improved premature infant survival dramatically. However, these agents may increase the risk for physical, neurological and behavior alterations. Anxiety, depression and attention difficulties are commonly described in adolescent and young adult survivors of prematurity. In the present study we administered vehicle, dexamethasone, or hydrocortisone to Sprague-Dawley rat pups on postnatal days 5 and 6, mimicking a short term clinical protocol commonly used in human infants. Two systems that are implicated in the regulation of stress and behavior were assessed: the limbic-hypothalamic-pituitary-adrenal axis [LHPA; glucocorticoid and mineralocorticoid receptors within] and the Serotonin (5-HT) system. We found that as adults, male Sprague-Dawley pups treated with GC showed agent specific altered growth, anxiety-related behavior, changes in corticoid response to novelty and gene expression changes within LHPA and 5-HT-related circuitry. The data suggest that prolonged GC-receptor stimulation during the early neonatal period can contribute to the development of individual differences in stress response and anxiety-related behavior later in life.

Psychobiological effects of prenatal glucocorticoid exposure in 10-year-old-children

BACKGROUND

Prenatal stress seems to have long-lasting effects on biological and psychological processes of the offspring. However, to date, there have been no studies investigating the effects of prenatal glucocorticoid exposure on psychological, endocrine, and autonomic responses to a standardized psychosocial stress test in children.

METHODS

A sample of 115 healthy, 10-year-old children was examined. The Glucocorticoids + Tocolytics group was characterized by tocolytic treatment of the mothers due to preterm labor (n = 43). In addition, the pregnant women received glucocorticoid treatment in order to accelerate fetal lung maturation in case of preterm birth. The first comparison group (Tocolytics) consisted of children whose mothers also experienced preterm labor, but did not receive glucocorticoid treatment (n = 35). In the second comparison group (CONTROL), children whose mothers had a complication-free pregnancy were assessed (n = 37). Psychological parameters (stress appraisal and mood) using self-report questionnaires as well as salivary cortisol, salivary alpha-amylase, and heart rate were measured during a standardized psychosocial stress test (Trier Social Stress Test for Children).

RESULTS

Group comparisons revealed that a subscale of stress appraisal, control expectancies, significantly differed in children who were prenatally exposed to glucocorticoids as compared to both comparison groups (F = 4.889, p = 0.009). Furthermore, significant differences between the groups were revealed for salivary cortisol. With respect to overall stress appraisal and heart rate, trends toward significance were observed between the three groups.

CONCLUSION

At the age of ten, those children who have been exposed to prenatal maternal glucocorticoids show changed psychobiological stress reactivity to a standardized psychosocial stress test as compared to control children.

Prenatal treatment with glucocorticoids sensitizes the hpa axis response to stress among full-term infants

The objective of this study was to determine the consequences for HPA axis functioning among healthy full-term newborns of prenatal treatment with the synthetic glucocorticoid (GC), betamethasone, which is the routine treatment for threatened preterm delivery. Ninety full-term infants were recruited into two study groups (30 betamethasone treated; 60 comparison group matched for GA at birth and sex). The cortisol and behavioral response to the painful stress of a heel-stick blood draw was assessed 24 hr after birth. Full-term infants exposed to prenatal betamethasone displayed a larger cortisol response to the heel-stick procedure, despite no differences in baseline levels. Further, within the recommended window of betamethasone administration (24-34 gestational weeks), infants exposed to betamethasone earlier in gestation displayed the largest cortisol response to the heel-stick. These data add to accumulating evidence that prenatal exposure to elevated GCs programs the development of the HPA axis.

Prenatal maternal stress programs infant stress regulation

OBJECTIVE

Prenatal exposure to inappropriate levels of glucocorticoids (GCs) and maternal stress are putative mechanisms for the fetal programming of later health outcomes. The current investigation examined the influence of prenatal maternal cortisol and maternal psychosocial stress on infant physiological and behavioral responses to stress.

METHODS

The study sample comprised 116 women and their full term infants. Maternal plasma cortisol and report of stress, anxiety and depression were assessed at 15, 19, 25, 31 and 36 + weeks' gestational age. Infant cortisol and behavioral responses to the painful stress of a heel-stick blood draw were evaluated at 24 hours after birth. The association between prenatal maternal measures and infant cortisol and behavioral stress responses was examined using hierarchical linear growth curve modeling.

RESULTS

A larger infant cortisol response to the heel-stick procedure was associated with exposure to elevated concentrations of maternal cortisol during the late second and third trimesters. Additionally, a slower rate of behavioral recovery from the painful stress of a heel-stick blood draw was predicted by elevated levels of maternal cortisol early in pregnancy as well as prenatal maternal psychosocial stress throughout gestation. These associations could not be explained by mode of delivery, prenatal medical history, socioeconomic status or child race, sex or birth order.

CONCLUSIONS

These data suggest that exposure to maternal cortisol and psychosocial stress exerts programming influences on the developing fetus with consequences for infant stress regulation.

Religion, spirituality, social support, and perceived stress in pregnant and postpartum Hispanic women

OBJECTIVE

To examine the association between religion/spirituality and perceived stress in prenatal and postpartum Hispanic women.

DESIGN

Cross-sectional survey.

SETTING

An urban, publicly funded hospital in California.

PARTICIPANTS

Two hundred and forty-eight pregnant and postpartum Hispanic women between age 18 and 45 years.

METHOD

Patients presenting for prenatal or postpartum care or for the first infant visit were recruited to participate in the current study. PARTICIPANTS completed surveys consisting of questions about demographic characteristics, religiosity, spirituality, social support, and stress.

RESULTS

Most participants were unmarried, low-income women with low educational attainment. Ninety percent of women reported a religious affiliation, with more than one half (57.4%) listing their religious affiliation as "Catholic." Overall religiousness/spirituality was significantly associated with increased negative experiences of stress in women who selected English language instruments (Spearman's r=.341, p=.007); there was no such relationship in women who selected Spanish language instruments. Social support and greater relationship quality with a significant other were significantly associated with reduced perceived stress in Spanish reading and English reading women.

CONCLUSIONS

In this sample of pregnant and postpartum Latinas, religiousness/spirituality was not associated with reduced perceived stress and was in fact associated with increased perceived stress among women who selected English-language surveys. Additional research is needed to investigate this association. On the other hand, the current study reinforces the importance of social support and relationship quality for pregnant and postpartum women.

Effect of antenatal betamethasone administration on neonatal cardiac autonomic balance

Beneficial effects of antenatal glucocorticoid treatment in pregnancies at risk for preterm delivery may entail long-term consequences for the establishment of sympathoadrenergic system balance. We analyzed the cardiac autonomic system activity in neonates with a single course of antenatal betamethasone (2 × 12 mg) treatment by calculating heart rate variability (HRV) time-domain parameters from 24 h ECG recordings and short-term frequency-domain parameters during infant active and resting states. In addition, resting and challenged salivary α-amylase levels were measured in 23 betamethasone-exposed neonates and compared with controls. Indicators for overall HRV (SDNN: p = 0.258; triangular index: p = 0.179) and sympathovagal balance [low- to high-frequency power (LF/HF): p = 0.82 (resting state)] were not significantly different in neonates of the betamethasone treatment group. Parameters mostly influenced by sympathetic activity [SD of the average of valid NN intervals (SDANN): p = 0.184 and SDs of all NN intervals (SDNNi): p = 0.784] and vagal tone [RMSSD: p = 1.0; NN50: p = 0.852; HF: p = 0.785 (resting state)] were unaltered. Resting α-amylase levels were not significantly different in the betamethasone treatment group (p = 0.304); however, α-amylase release after a neonatal challenge was slightly reduced (p = 0.045). Thus, cardiac autonomic balance seems to be preserved in neonates exposed to a single course of antenatal betamethasone treatment.

The timing of prenatal exposure to maternal cortisol and psychosocial stress is associated with human infant cognitive development

The consequences of prenatal maternal stress for development were examined in 125 full-term infants at 3, 6, and 12 months of age. Maternal cortisol and psychological state were evaluated 5 times during pregnancy. Exposure to elevated concentrations of cortisol early in gestation was associated with a slower rate of development over the 1st year and lower mental development scores at 12 months. Elevated levels of maternal cortisol late in gestation, however, were associated with accelerated cognitive development and higher scores at 12 months. Elevated levels of maternal pregnancy-specific anxiety early in pregnancy were independently associated with lower 12-month mental development scores. These data suggest that maternal cortisol and pregnancy-specific anxiety have programming influences on the developing fetus.